April
6, 2008 (Bloomberg) -- Mud clay, used as a folk remedy to heal
wounds, soothe indigestion and beautify the complexion, may help
doctors fight drug-resistant infections.

In tests of
more than 30 clay samples from around the world, researchers
found clays from Oregon and Nevada that killed almost all the
cells of methicillin-resistant Staphylococcus auereus, a staph
infection that can be fatal, according to Arizona State
University researchers. The results are being presented today at
the American Chemical Society meeting in New Orleans.

While clay
today is mostly associated with the mud baths of health spas,
people have used it for thousands of years to treat ailments, by
eating it or applying it to the skin. If the study findings hold
up in human tests, doctors may have new ways to combat
infections, the researchers said. The study, funded by the
National Institutes of Health, is the first to look at the
antibacterial activity of natural clay.

``Since people
existed, they have used clays for medicinal purposes,'' said
Lynda Williams, a research professor at Arizona State
University, in Tempe, in an telephone interview on April 2. ``If
we can understand its antibacterial mechanism, then I expect
clays will be more prevalent in people's lives.''

The Oregon and
Nevada samples also killed almost all cells of E. coli, which
causes food poisoning, and destroyed pseudomonas aeruginosa,
which causes urinary tract and gastrointestinal infections, as
well as deadly infections in people hospitalized with cancer and
burns.

A French clay
was also effective against MRSA, pseudomonas aeruginosa and E.
coli, said researcher Shelley Haydel, an assistant professor of
life sciences at Arizona State.

Clay for MRSA

More than
94,000 invasive MRSA infections occurred in the U.S. in 2005,
resulting in 18,650 deaths, according to the latest estimates by
the U.S. Centers for Disease Control and Prevention. Healing
clay might be turned into rub-on creams or ointments to keep
MRSA infections from spreading, researchers said.

The scientists
theorize that chemicals in the clay may kill bacteria by poking
holes in the cells.

``We believe
right now it's the chemistries of the clays themselves,'' Haydel
said in a telephone interview on April 2. ``We don't have a
definitive answer.''

The researchers
are planning to study the clay as a topical remedy for wound
infections. Until those tests are done, people should be
cautious because natural clay also contains toxic minerals such
as mercury and arsenic, Williams said.

Whether doctors
will embrace clay as a treatment for infections remains to be
seen, the researchers said.